Physics 10-29-15 Friction & Forces on an Incline Problems Review

PHYSICS: Girl on a sled coasts down a hill, box is pushed up a hill… Is it starting to make a little more sense? I thought a look at a couple other problems might be helpful, so below today’s vodcast of #52 and 40, I put a vodcast from last year with problems #46 and 48.

Here’s the thing. You can watch me or someone else do a thousand problems (okay, maybe not a thousand – but a lot!), and it won’t help. That’s what today was about. I don’t want you to copy what I do, I want you copy why I’m doing it. Make sense? You’re getting it…keep sledding and watch out for net forces!

Physics 10-29-15 Friction & Forces on an Incline Problems Review from Tammy Skinner on Vimeo.

flick photo by Eva the Weaver

PHYSICS 11-10-14 Friction & Forces on an Incline Problems Review from Tammy Skinner on Vimeo.

flickr photo by darkmatter

Physics 10-28-15 Friction Problems & Friction on Inclines

PHYSICS: Who knew snow skiing could be so complicated! Well…friction problems on an incline anyway. Here’s the problem review from the homework and then our discussion of friction problems on an incline.

Back to the problems – remember, drawing the diagram is super, super important. Label all the forces and apply the concepts you know about net forces and resultant forces – let it tell you a story. πŸ™‚

Here is some info you might find helpful:
Wed night answers

Physics 10-28-15 Friction Problems & Friction on Inclines from Tammy Skinner on Vimeo.
flickr photo by t i g

Hon Chemistry 10-28-15 Empirical & Molecular Formulas

HON CHEMISTRY: Awesome job today!! You just about figured out how to find an empirical formula all by yourself! I love the way you were able to think through what you knew and what you needed to find a solution!

Be sure and practice – if you don’t it’ll get all turned around and you’ll end up leaving off an important step. The hardest part is that it’s not a set formula for you to plug and play, but if you’ll keep in mind that you’re really just looking for subscripts which are just moles, you’ll be able to think it through. Percent to mass, mass to moles, moles to smallest whole number ratio.

Are you starting to catch on to the steps? It will be good for you to memorize them, but would it not be just tons better to understand why you need each step – backwards and forwards, so then you wouldn’t need to memorize them at all!

And then, also remember what molecular formulas are – just a multiple of the empirical formula. Keep that concept in mind, and you’ll have no problem remembering to divide the molecular formula mass by the empirical formula mass to find X! Easy peasy! πŸ™‚

On a different subject, need some extra practice on chemical formulas and moles?? Help Session this Friday morning, 7:30 A.M.

Hon Chemistry 10-28-15 Empirical & Molecular Formulas from Tammy Skinner on Vimeo.

flickr photo by Darwin Bell

Hon Chemistry 10-27-15 Percent Composition

HON CHEMISTRY: Great job today… although, it was really weird watching you chew gum in class! Don’t forget to continue to think like a scientist as you write up your lab report (data table, calculations, units, sig figs, etc.)! Also, be sure to include as part of your conclusion reasons for any error you might have had or why you didn’t have any at all.

I think you’ll find that percent composition problems are super easy to catch on to. Make sure, though, you can write chemical formulas (I won’t give them to you!) and that you’ve memorized the formulas for acids and those common substances from #58. It’s just plug and play from there! πŸ™‚

Hon Chemistry 10-27-15 Percent Composition from Tammy Skinner on Vimeo.

flickr photo by ΀ϊ΢΢Β₯

Chemistry 10-27-15 Practicing Chemical Formulas

CHEMISTRY: Does writing and naming chemical formulas tie you in knots? I hope today’s practice helped!

The first vodcast below is the work we did in class going over last night’s homework: #20, 21, and 48. Keep working on it! The knots are all going to come unraveled and you are going to master this!!

Below the class vodcast is the help session from this morning. Holler if you’d like to have another help session!

Chemistry 10-27-15 Practicing Chemical Formulas from Tammy Skinner on Vimeo.

flickr photo by Elizabeth The Queen Of All Things

Chemistry Help Session 10-27-15 Chemical Formulas from Tammy Skinner on Vimeo.

Physics 10-27-15 Friction & Normal Force

PHYSICS: Why don’t things that are moving just keep moving? Here is our intro on friction from today

Remember a few key things. One of the most important – net forces produce acceleration.

You can find Ff a couple of different ways – it’ll be part of a net force equation and can be found from the coefficient of friction equation. If and ONLY if your object is moving at a constant velocity, Ff will equal Fa. Fn is only sometimes equal to Fw. If your object is pulled at any angle (or pushed), Fn will be a part of Fnet in the vertical direction.

Whew!
πŸ™‚

Physics 10-27-15 Friction & Normal Force from Tammy Skinner on Vimeo.

flickr photo by kbaird

Chemistry 10-26-15 Oxidation Numbers

CHEMISTRY: One man’s rust is another student’s lesson in chemistry! Here’s the lecture from today on oxidation numbers. Now it’s time to go and practice applying them! Need help? Help session tomorrow morning at 7:20ish A.M.

How did you do on the polyatomic ion quiz? And what about the pre-test on all the memorization FRIDAY? For the pre-test you need to have memorized (and be able to use!!): polyatomic ions, monatomic ions (but you can get these off the periodic table), acids, prefixes, the chemical names and formulas of common substances, and how to apply the oxidation rules to write and name chemical formulas.

That’s a lot, but you can do it! And make double dog sure you are working hard at memorizing it all now!!

Chemistry 10-26-15 Oxidation Numbers from Tammy Skinner on Vimeo.

flickr photo by scottwillis

Physics 10-26-15 Newton’s 2nd & 3rd Laws

PHYSICS: So an object at rest can be at equilibrium, but what about an object that is moving? And how does equilibrium relate to Newton’s first law? Or Newton’s second law? And what if you don’t have balanced forces. Here’s the lecture from today on just that! Now remind me, net forces produce what?

Oh, and while we’re at it, you’d rather hit a hay stack than a brick wall why? (Thanks, Austin, for being such a great sport!)

And, for your viewing pleasure, enlightenment and overall edification – Julius Sumner Miller on Newton’s Second and Third Laws. Good stuff! you’ll find them extremely helpful with the conceptual part of the test. I strongly encourage you to watch them!

Physics 10-26-15 Newton's 2nd & 3rd Laws from Tammy Skinner on Vimeo.

Photo: Joe Armao

Physics 10-22-15 A Woodpecker & ZORBA

PHYSICS: Awesome job working through the woodpecker and Zorba problems today. Loved, loved, loved watching you brainstorming, collaborating, and applying information you’ve previously learned!!

Now can you go and do the Zorba problem on your own?

Physics 10-22-15 A Woodpecker & ZORBA from Tammy Skinner on Vimeo.

flickr photo by Claudio Gennari

Chemistry 10-22-15 Binary Molecular Formulas

CHEMISTRY: Do you feel like you have letter and numbers swimming in your eyes? This is one of those times that paying attention to details is super, super important! Here’s the lecture from today on writing formulas and names for binary molecular compounds. Part of it’s really similar to what you learned to do last week for ionic compounds, but another part is totally different. Details!!

Make sure you keep everything straight. Do something that will organize all the information for you, so you won’t get confused. Also, don’t forget the lists you have to memorize, especially the one for MONDAY – polyatomic ions!! And practice, practice, practice!!!

Help Session??

Chemistry 10-22-15 Binary Molecular Formulas from Tammy Skinner on Vimeo.

flickr photo by Roger Smith